Fraunhofer response and supercurrent spin-switching in Black Phosphorus with strain and impurity. (arXiv:1811.00027v1 [cond-mat.mtrl-sci])

//Fraunhofer response and supercurrent spin-switching in Black Phosphorus with strain and impurity. (arXiv:1811.00027v1 [cond-mat.mtrl-sci])

We develop theory models for both ballistic and disordered superconducting black phosphorus devices in the presence of magnetic exchange field and stress. The ballistic case is studied through a microscopic Bogoliubov-de Gennes formalism while for the disordered case we formulate a quasiclassical model. Utilizing the two models, we theoretically study the response of supercurrent to an externally applied magnetic field in two-dimensional black phosphorus Josephson junctions. Our results demonstrate that the response of the supercurrent to a perpendicular magnetic field in ballistic samples can deviate from the standard Fraunhofer interference pattern when the Fermi level and mechanical stress are varied. This finding suggests the combination of chemical potential and strain as an efficient external knob to control the current response in high-sensitive strain-effect transistors and SQUIDs. We also study the supercurrent in a superconductor-ferromagnet-ferromagnet-superconductor junction where the magnetizations of the two adjacent magnetized regions are uniform with misaligned orientations. We show that the magnetization misalignment can control the excitation of higher harmonics than the first harmonic $sin varphi$ (in which $varphi$ is the phase difference between the superconductors) in supercurrent and constitutes a full spin switching current element. Finally, we discuss possible experimental implementations of our findings. We foresee our models and discussions can provide guidelines to experimentalists in designing devices and future investigations.

Published in: "arXiv Material Science".

2018-11-02T02:29:23+00:00November 2nd, 2018|Categories: Publications|Tags: |
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